With Proposition 2, legislators are asking voters to approve a $2 billion bond the legislature approved in 2016 to fund housing for mentally ill Californians throughout the state. Lawmakers want to finance the bond with revenue from California’s 1 percent tax on millionaires, which voters approved in 2004 when they passed Proposition 63.

Supporters of both propositions have organized “Affordable Housing Now,” a committee advocating for both bond measures. Facebook’s Mark Zuckerberg and his wife Priscilla Chan have contributed $250,000. The real estate investment firm Essex Property Trust and a committee funded by labor unions representing engineers and maintenance workers have both contributed $150,000 to the “Yes on 1 and 2” effort.